Well-drilling tool



June 11, 1929. H AFEL 1,716,741

r zj/ WELL DRILLING TooL Filed Nov. 13 1928 INVENTOR.

I 0% 56/? Wdf2 v m ATTORNEYS.

Patented ll,

. MICHAEL SCHWAFEL, GE TAFT, @ALIFGBNI IA.

ELL-DRILLING TQGL.

Application filed November 13, 1928. Serial No. 819,08.

Y lhis invention relates to well drilling tools such as are used in the drilling of oil wells and thelike and has special reference to a rotary well drilling bit.

One important object of the invention is I to improve the general construction of de vices of this dial-actor.-

A second important object of the invention is to provide an improved self sharpen- .ing bit for well drilling.

A third important object of the invention .is to provide an improved bit having rotate ably changeable cutters so arranged that the cutters out of service are automatically sharpened by the effects of the drilling operation. a 7

With the above and other objects in view as will be hereinafter'apparent the invention consists in general of certain novel details of construrtion and combinations of parts hereinafter fully described, illustrated inthe accompanying drawings and specifically claimed.

In the accompanying drawings like charactors of reference indicate like parts in the elevation of a drill with this in- I F] gure 1.

Figure 3 is asection on the line 3-3 of Figure 1. v

Figure 4 is a SOCt10I1 OH the line H of Figure 2. v

Figure 5 IS a section on the line 55 of Figure 1.

ln the construction ofthe bit as here shown there is provided a body from which depends the parallel arms 11 rounded on their outer sides and having downwardly extending cuttingvedges .12 projecting from the outer portions of their ends. The upper end of the body terminates in a threaded boss 13 for attachment of the bit to the hollow drill stem commonly used in rotary well boring. Between the arms 11 extends shaft 14 and on thisshaitis pivoted a rotary cutter blade unitconsisting of two pairs oft blades 15 one pair on each side of the median plane and the blades of each pair extending in opposite directions from theshatt 1st. Each of these blades has a concave forward face 16 and a convex rear face 17 approaching each other at the blade edge which is formed by beveling off the concave edge portion as at 18.

One of the armsll is provided'with a recess 18 wherein is pivoted a beveled pawl 19 pressed outward by a spring 20. This pawl is arranged to engage the rear sides of the upwardly extending blades of the pair of blades adjacent the said arm so that the blades will not rotate upon the bit being rotated in the cutting direction but the bevel of the pawl permits the blades to rotate readily in the opposite direction. 7

in the other arm 11 is a recess 21 wherein is mounted a pawl 22 which is held norin'allyretracted by a leaf spring 23 engaged against a collar 24 formed'on a stem 25 projccting inwardly of the recess from the pawl 22. A forked cam member 26 is slidably mounted in said recess to have its arms straddle the inner end of the stem 25 and the bottom of the forked portion is beveled .as at 27 to wedge the stem and pawl out- .wardly of the recess against the action of the spring 2-3. This projects the pawl behind to convex side 17 of that blade 15 of the remaining pair. which extends upwardly from the shaft, the blades under theseeon ditions being locked from rotation in either direction by the action of the two pawls.

Wardlyby the operator.so'that the idle cutting edges may be'turned down into cutting position and the previously used edge turned upwardly into sharpening position.

Through the body ll) and head 13 extends a passage 30 having its lower end branched to open on opposite sides of the head as at 31. These passages-carry off the grit and mud from the bottomof the hole and this grit and mud flowing, in the direction of the. arrows in l igure 1' rubs-against the beveled portions of theupturned idle blades and thus effectually sharpens them.

llhere has thus been provided a simple and eflicient device ofthe kind described and tor the purpose specified.

It is obvious that minor ,changes may be made in the form andconstruction of the invention without departing from the material spirit thereof. It is not, therefore, desired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly come within the scope claimed.

Having thus described the'invention, what is claimed as new, is: i v

1. In a well drill bit, a forked body, a rotatable cutter blade member mounted in the fork to revolve on a horizontal axis, means to limit rotation of the member to one direction only, and means controlled by the position of the bit in a well-and arranged to lock said member against rotation upon the bit being lowered to boring position.

2. In a well drill bit, a forked body, a rotatable cutter blade member mounted in the fork to revolve on a horizontal axis, means tolimit rotation ofthe member to dne direction only, a stop carried by one arm of the fork and projectable into the path of revolution of the cutter member, said stop being normally retracted from said path, and means to project said stop into said path and including a stem normally projecting downwardly from the head to engage the bottom of the drill hole and be forced upwardly of said head. 4

'3. In a well drill bit, a forked body, a rotatable cutter blade member mounted in the fork to revolve on ahorizontal axis, means to limit rotation of the member to one direction only, a stopcarried by one arm of the fork and projectable into'the path of revolution of the cutter member, said stop being normally re- ,tracted from said path, means to project said stop into said path and'including a stem normally projecting. downwardly from the head to engage the bottom of the drill hole and be forced upwardly of said head, a spring normally holding said stop retracted,

and a second spring normally holding said stem protracted.

l. in a well drill bit, a forked bod a rotatable cutter blade member mounte in the fork to revolve on a horizontal axis, a pawl carried by one arm of the fork and spring pressed into. the path of said cutter member, said pawl having one face beveled and a second face at right angles to the path of said cutter member whereby the cutter member may rotate past the pawl in one direction and be stopped by the pawl uponinovement in the opposite direction, and means con trolled by the position of the bit in a well and. arranged to locksaid member againstrotation upon the bit being lowered to bon. ing position.

5. in a well drill bit, a forked body, a rotatable cutter blade'member mounted in the fork to revolve on a horizontal axis, a pawl carried by one arm of the fork and spring pressed into the path of said cutter member, said pawl having one face beveled and a second face at right angles to the path of said cutter member whereby the cutter member may rotate past the pawl in one and be forced upwardly of said head.

6. In a well drill bit, a forked body, a rotatable cutter blade member mounted in the fork to revolve on a horizontal axis, a pawl carried by one arm of the fork and spring pressed into the path of said cutter member, said pawl having one face beveled and a second face at right angles to the path.

of said cutter member whereby the cutter member may rotate past the pawl. in one direction and be stopped by the pawl upon movement in the opposite direction, a stop carried by one arm of the fork and projectable into the path of revolution of the cutter member, said stop being normally retracted from said path, meansto project said stop into said path and including a stem normally projecting downwardly from the head to engage the bottom of the drill hole and be forced upwardly of said head, a spring normally holding said stop retracted, and a second spring normally holding said stem protractel. r

7. In a well drill bit, a forked body, a rotatable cutter.v blade member mounted in the fork to revolve on a horizontal axis, said cutter meinbe'r consisting of two double ended cutters arranged on opposite sides of the axis of revolution of the bit and connected to revolve together, each end of each cutter being provided with a sharp cutting edge at its free end, one end of each cutter projecting downwardly into working position and the other end projecting upwardly, means to limit rotation of the member to one direction only, and means controlled by the osition of the bit in a well and arran ed Z to lock said member against rotation upon the bit being lowered to boring position.

8. in a well drill bit, forked body, a rotatable cutter blademember mounted in the fork to revolve on a horizontal axis, said cutter member consisting of' two double ended cutters arranged on opposite sides of the axis of revolution of the bit and connected to revolve together, each end of each cutter being provided with a sharp cutting edge at its free end, one,end of each cutter projecting downwardly into working position and the other end projecting up wardly, means to limit rotation of the member to one direction only, a step,

carried byone arm of the :tork and'projectable into the path of revolution of the cutter member, said stop being normally retracted from said path, and means to project said stop into said path and including a stem normally projecting downwardly tion and the other end projecting upwardly,

means to limit rotation of the member to one direction only, a stop carried by one arm of the fork and projeetable into the path of revolution of the cutter member, said stop being normally retracted from said path,

means to project said stop into said pathand Including a stem normally pro ecting.

downwardly from the head to engage thebottom of the drill hole and be forced upwardly of said head, a spring normally holding said stop retracted, and a second spring'norma-lly holding said stem protracted. I r

10. In a well drill bit, a forked body, a rotatable cutter blade member mounted in the fork to revolve on a-horizontal axis, said cutter member consisting of two double ended cutters arranged on opposite sides of the axis of revolution of the bitand eonnectcd to revolve together, each end of each cutter being provided with a sharp cutting edge at its free end, one end of each cutterpro ecting downwardly into working position and the other end projecting upwardly,

a pawl carried by one arm of the fork and spring pressed into the path of said cutter mcmber,said pawl having one face beveled and a second face, at right angles to the path of said cutter member whereby the 'cutter membermay rotate past the pawl in one di- ,rection and be stoppedby the pawl upon movement in the opposite direction, and means controlled by the position of the bit,

in awell andarranged-to'lock said member against rotation upon the bit being lowered n nected to revolve together, each end or each to boring position. i

11. In a well drilhbit, a forked body, a rotatable cu-tter blade member mounted in the fork to revolveona horizontal axis, said cutter member consisting of two double ended cutters arranged on oppositesides of the axis of revolution ot the bit and connected to'revolve together, each end of. each cutter being. provided with a sharp cutting edge at its free end, one end of each-cutter.

projecting downwardly into working position and the other end projecting upwardly, a pawl carried by one arm o1 thei orlr and spring pressed into the path of said-cutter member, said pawl having one face beveled and a second race at right angles to the path of said cutter member whereby theciitter member may rotate past the pawl in one direction and be stopped bythe pawl upon anovement in the opposite direction, a stop carried by one arm of the fork'and projectable into the path of revolution of the out ter -1nember, said stop being normally rctracted from said path, and means to project said stop into said path and including a stem normally projecting downwardly from the head to engage the bottom of the drill hole and be torced upwardly ot said head. v v

12. In a well drill bit, a forked body, a rotatable cutter blade member mounted in the fork to revolve on a horizontal axis, said cutter member consisting of two double ended cutters arranged on opposite sides of the axis of revolution of the bit and connected to revolve together, each end of each cutter being provided with a sharp cutting edge at its free end, one end of each cutter projecting downwardly into working position and the other end projecting upwardly,

a pawl carried by one arm of the fork and spring pressed into the path of said cutter member, said pawl having. one face beveled and a second face at right angles to the path of s'aid cutter member whereby the cutter member may rotate past thepawl in one direction and be stopped by the pawl upon movement in the opposite direction, a stop carried by one arm of the fork and projectable into the path of revolution of the cutter member, said stop being normally retracted from said path, means to project said stop into said path and including a stein normally projecting downwardly from the head to engage the bottom ofthe drill hole and be forcedup'wardly of said head, a sprimt normally holding said stop retracted, and a second springnormally holding said steinv protracted. Y

13. In a well drill bit, a forked body, a rotatablecutter blade member mounted in the fork to revolve on'a horizontal axis, said cutter member consisting of two double ended cutters arranged onopposite sides of the axis of revolution of the bit and concutter bcing'provided with a sharp cutting edge at its free end, one end 01" ea h cutter projecting downwardly into wor' ilng position andthe other end projecting upwardly, means to limit rotation of the member to one direction only, and means controlledby the position of the bit in a well and arranged to lock said member against rotation upon the bit being lowered to boring position,

' cutterends and to one side there said bit body being provided with sludge passages terminating downwardly in ports positioned above the upwardly project-ing 0 whereby sludge passing into said'ports will flow over the upper edge portions of the cutters to sharpen the same.

14. In a Well drill bit, a forked body, a rotatable cutter blade member mounted in the fork to revolve on a horizontal axis, said cutter member consisting of two double ended cutters arranged on opposlte sides of the axis of revolution of the bit and connected to revolve together, each end of each cutter being provided with a sharp cutting edge at its free end, one end of each cutter projecting downwardly into working position and the other end projecting upwardly, means to limit rotation of the member to one direction only, a stop carried by one arm of the fork and projectable into the path of.

revolution of the cutter member, said stop being normally retracted from said path, and means to project said stop into said path and including a stem normally projecting downwardly from the head to engage the bottom ofthe drill hole and be forced upwardly of saidhead, said bit body being provided with sludge passages terminating cutter being provided with a sharp. cutting edge at its fre end, one end of each'cutter projecting downwardly into working position and the other end projecting upwardly, means to limit rotation of the member to one direction only, a stop carried by one arm of the fork and projectable into the path of revolution of the cutter member, said stop being normally retracted from said path,

means to project said stop into said path and including a stem normally projecting downwardly from the head to engage the bottom of the drill hole and be forced upwardly of said head, a spring normallyholding said stop retracted,.and' a second spring normally holding said stem protracted, said bit body being provided with sludge passages terminating downwardly in ports positioned above theupwardly projecting cutter ends and to one side thereof whereby sludge passing into said ports will flow over the upper edge portions of the cutters to sharpen the same. i

16. a well drill bit, a forked body,- a

rotatable cutter blade member mounted in the fork to revolve onahorizontal axis, said cutter member consisting of two double ended cutters arrangedon opposite sides of the axis of revolution of the bit and connected to revolve together, each end of each cutter .being provlded with a sharp cutting edge at its free end, one end of each cutter projecting downwardly into working position and, the other end projecting upwardly, a pawl carried by one arm of the fork and spring pressed into the path of said cutter membergrsaid' awl having one face beveled and a second ace at rightangles to the path of said cutter member whereby the cutter membcr may rotate past the pawl in one direction and be stopped by the pawlupon movement in the opposite direction, and means controlled by the position of the bit in a well and arranged to locksaid member against rotation upon the bit being lowered to boring position, said bit body being provided with sludgepassages terminating downwardly in ports positioned above the upwardly projecting cutter-ends and to one side thereof whereby sludge passing into said ports will flow over the upper edge portions of the cutters to sharpen the same.

17. In a well drill bit, a forkedbody, a rotatable cutter blade member mounted in the fork to revolve on a horizontal axis, said cutter member consisting of two double ended cutters arranged on opposite sides of the axis of revolution of the bit and connected to revolve together, each end of each cutter being provided with a sharp cutting edge at its free end, one end ofeach cutter projectingdownwardly into working position and the other end projecting upwardly, a pawl carried by one arm of the fork and spring pressed into the path of said cutter member, said pawl having one face beveled and a second face at right angles to the path of said cutter member whereby the cutter v member may rotate past the pawl in one direction and be stopped by the pawl upon movement in the opposite direction, a stop carried by one arm of the fork and projectable into the path of revolution of the cutter member, said stop being normally reftracted from said path, and means to projec't said stop into said path and including a stem normally projecting. downwardly from the head to engage the bottom of the drill hole and be forced upwardly of said head, said bit body being provided with sludge passages terminating downwardly in ports positioned above the upwardly projectingcutter ends and tooneside thereof whereby sludge passing into said ports -will flow over the upper edge portions of the cutters to sharpen the same.

18. in a well drill bit, a forked body, a

rotatable cutter blade member mounted in the fork to revolve on a horizontal axis, said cutter member consisting of two double ended cutters arranged on opposite sides of" the axis of revolution of the bit and connected to revolve together, each end of each cutter being provided with a sharp cutting edge at its free end, one end of each cutter projecting downwardly into working position and the other end projecting upwardly, a pawl carried by one arm of the fork and spring pressed into the path of said cutter member, said pawl having one face beveled and a second face at right angles to the path of said cutter member whereby the cutter member may rotate past the pawlin'one direction and be stopped by the pawl upon movement in the opposite direction, a stop carried by one arm of the fork and projectable into the path of revolution of the cut ter member, said stop being normally retracted from said path, means to project said stop into said path and including a stem normally projecting downwardly from the head to engage the bottom of'the drill hole and be forced upwardly of said head, a spring normally holding said stop retracted, and a second spring normally holding said stein protracted, said bit body being provided with sludge passages terminating downwardly in ports positioned above the upwardly projecting cutter ends and to one side thereof whereby sludge passing into said ports will flow over the upper edge portions of the cutters to sharpen the same.

In testimony whereof I aflix my signature.

MICHAEL soHw FnL; 

